Improvement in compositions for working steel



UNITED, STATES PATENT OFFICE.

HORACE VAUGHN, or rnovrnnnon, RHODE' ISLAND.

IMPROVEMENT IN COMPOSITIONS FOR WORKING STEEL.

Specification forming part of Letters Patent No. 15,16l, dated June 17, 1856.

To all whom itmay, concern.

Be it known that I, HORACE VAUGHN, of the city and county of Providence, and State of Rhode Island, have invented a new and Improved Method of Hardening and Tempering about one-fourth of that of the old.

. Third. It leaves a smooth surface and does not scale.

Fourth. It does not crack, split, warp, or spring after being thus prepared.

Fifth. The more it is heated and hardened the finer and stronger it grows, and this efi'ect is just the reverse of that by the old method. Sixth. Cast-iron is effectually hardened in such parts as are the more subject to friction or .wear.

I will now describe the nature of the composition, and then of the'method of applying the same in order to efl'ectthe desired object...

There are several known compositions of chemical matter which have been used from time to time in hopes of cfi'ectin g these results, and none of them have as yet been more than partiallysuccessful. Chemical solutions or materials in a liquid state have been the agents often adopted. Solids have been and are now in common usesuch as borax, prussiate of potash, &c.and these, as well as the fluids, are applied at various and generally high stages ot'heat. The materials mentioned as solids and now in use fall far behind the composition or mixed ingredients used by me, asdo the fluidsbehind them, since the volatile part of the latter are so speedily evaporated by the heat as to leave their effect, when applied to heated. steel, but trifling. The mixture, however, of the bichromate and prussiate of potash with chloride of sodium in certain proportions will I effect every and all the results we have claimed as the advantages of this over the ordinary.

system of hardening and tempering, and this is done at comparatively low stages of heat when compared with the old method. This- 'composition is used in a dry pulverized (finely) state and in about the following proportions, viz: two ounces of bichromate of potash,

fourteen ounces 'of prussiate of potash, and

seventeen ounces of chloride of sodium. These numbers are not imperative, but are found as good as any in practice; or the chloride of sodium may be used with either the biehromate or the prussiate of potash or articles possessing similar chemical properties as these latter, but in this case the proportion of either of the latter to the. chloride of sodium would be aboutas sixteen to seventeen. The work to be done (the kind of work) would, however, regulate these proportions in a great measure,-- Having fully explainedthe compound, I will i only add that it must be finely pulverized, put

in a common dredging-box, and from this shaken upon the metal when of proper tem perature to receive it. In order to clearly un- (lerstand when the metal is thus ready 'it will be necessary to speak in detail of the manner of dealing with a few articles, classified according to the requisite degree of heat.

Dies for heading screws. dies for transferring from steel to or upon steel, and trip-hammer dies,&c., will be considered as the first class for illustration. Heat the steel so that it wood is drawn across it sparks will be freely thrown out. Thensiftthecompositionevenlyandfreely upon it. Return the steel to a slow and even-1 fire until it is nearly or quite cherry red, and it anexceeding hard and deep temper is required apply the composition a second time at cherry heat, and almost immediately plunge it into cold water.

For the second class-such asfluted reamers, cutters, and large taps-harden by a shade less in degree of heat than cherry red, and sprinkle with the composition but once, then plunge into cold water.

For the third class-such as small taps and drills for drilling iron-a less degree of heat than the last, sprinkle with composition, and soon plunge into cold water.

Fourth class-such as chisels, gages, and

- What I claim as my invention, and desire to secure by Letters Patent, is-- The dry compound of chloride ofsodium and 'bichromate of p0tash,-with or without the prusslate of potash, for hardening and tempering steel, combined, applied, and operating substantially as is herein set forth.

HORACE VAUGHN.

In presence of- RHEMIAH KEEN, GEO. G. THOMAS. 

